Metallic channel devices (e.g. transistors) use metallic channels that are the natural extension of highly-doped Si nanowire. Metallic junction-less field-effect transistors (FETs) benefit from a number of advantages including the reduction in the source and drain resistances, simple fabrication processes, and high values of transistor ON current. In a metallic junction-less FET device, a source-drain current can flow through the metallic channel, when the gate terminals are at zero bias voltage (e.g., ON state), and the source-drain current flow is stopped by biasing the gate terminal with a sufficiently negative voltage (e.g., OFF state). It is understood that the most desirable channel materials are expected to exhibit conductance close to that of a metal.
Due to high concentration of electrons in metals, penetration of electric filed in metals is prevented by the screening effect of the electrons. In order to observe field effect in metallic film, the thickness of the metallic film should be or the order of a screening length (e.g., about 2 nm). The electron concentration in a metal can be reduced to combat screening effect by precise doping of impurities into the metal. Doped metallic layers can be deposited by metal deposition techniques including sputtering and thermal evaporation. These techniques may not allow precise control the growth rate, film thickness, and composition at atomic scale.